Filtering method, moving picture coding apparatus, moving picture decoding apparatus, and moving picture coding and decoding apparatus

Abstract

A filtering method according to the present invention is for filtering a plurality of blocks included in an image, and comprises: determining whether each of the blocks is an IPCM block or not; filtering a non-IPCM block that is not an IPCM block among the blocks to generate filtered data; outputting the filtered data as pixel values of the non-IPCM block, and outputting pixel values of the unfiltered IPCM block as pixel values of the IPCM block.

The invention claimed is: 
     
       1. A coding and decoding apparatus which encodes a first image on a block-by-block basis, and decodes a second image from an encoded bitstream on a block-by-block basis, the coding and decoding apparatus comprising:
 a first filtering unit configured to filter a first block and a second block included in the first image to generate first filtered data, using values of pixels respectively included in the first block and the second block, each of the first block and the second block being either a first Intra Pulse Code Modulation (IPCM) block or a first non-IPCM block; 
 a first determining unit configured to determine (i) whether both of the first block and the second block are first non-IPCM blocks; (ii) whether both of the first block and the second block are first IPCM blocks; or (iii) whether one of the first block and the second block is a first IPCM block and the other of the first block and the second block is a first non-IPCM block; and 
 a first reconstructing unit configured to generate, when it is determined by said first determining unit that one of the first block and the second block is a first IPCM block and the other of the first block and the second block is a first non-IPCM block, a first reconstructed image, 
 wherein the first reconstructed image includes (i) a part of the first filtered data generated by said first filtering unit as the pixels in the first non-IPCM block and (ii) unfiltered pixels in the first IPCM block, instead of a part of the first filtered data generated by said first filtering unit, as the pixels in the first IPCM block, 
 wherein prediction and transformation are performed on the first non-IPCM block, and prediction and transformation are not performed on the first IPCM block, 
 wherein the first block is adjacent to the second block, and 
 wherein in the filtering of the first block and the second block, a fixed value is not used as a first quantization parameter of a first IPCM block, 
 wherein the coding and decoding apparatus further comprises: 
 a second filtering unit configured to filter a third block and a fourth block included in the second image to generate second filtered data, using values of pixels respectively included in the third block and the fourth block, each of the third block and the fourth block being either a second Intra Pulse Code Modulation (IPCM) block or a second non-IPCM block; 
 a second determining unit configured to determine (i) whether both of the third block and the fourth block are second non-IPCM blocks; (ii) whether both of the third block and the fourth block are second IPCM blocks; or (iii) whether one of the third block and the fourth block is a second IPCM block and the other of the third block and the fourth block is a second non-IPCM block; and 
 a second reconstructing unit configured to generate, when it is determined by said second determining unit that one of the third block and the fourth block is a second IPCM block and the other of the third block and the fourth block is a second non-IPCM block, a second reconstructed image, 
 wherein the second reconstructed image includes (i) a part of the second filtered data generated by said second filtering unit as the pixels in the second non-IPCM block and (ii) unfiltered pixels in the second IPCM block, instead of a part of the second filtered data generated by said second filtering unit, as the pixels in the second IPCM block, 
 wherein prediction and transformation are performed on the second non-IPCM block, and prediction and transformation are not performed on the second IPCM block, 
 wherein the third block is adjacent to the fourth block, and 
 wherein in the filtering of the third block and the fourth block, a fixed value is not used as a second quantization parameter of a second IPCM block. 
 
     
     
       2. A coding and decoding apparatus which encodes a first image on a block-by-block basis, and decodes a second image from an encoded bitstream on a block-by-block basis, the coding and decoding apparatus comprising:
 processing circuitry; and 
 storage coupled to the processing circuitry, 
 wherein the processing circuitry is configured to: 
 filter a first block and a second block included in the first image to generate first filtered data, using values of pixels respectively included in the first block and the second block, each of the first block and the second block being either a first Intra Pulse Code Modulation (IPCM) block or a first non-IPCM block; 
 determine (i) whether both of the first block and the second block are first non-IPCM blocks; (ii) whether both of the first block and the second block are first IPCM blocks; or (iii) whether one of the first block and the second block is a first IPCM block and the other of the first block and the second block is a first non-IPCM block; and 
 generate, when it is determined that one of the first block and the second block is a first IPCM block and the other of the first block and the second block is a first non-IPCM block, a first reconstructed image, 
 wherein the first reconstructed image includes (i) a part of the first filtered data as the pixels in the first non-IPCM block and (ii) unfiltered pixels in the first IPCM block, instead of a part of the first filtered data, as the pixels in the first IPCM block, 
 wherein prediction and transformation are performed on the first non-IPCM block, and prediction and transformation are not performed on the first IPCM block, 
 wherein the first block is adjacent to the second block, and 
 wherein in the filtering of the first block and the second block, a fixed value is not used as a first quantization parameter of a first IPCM block, 
 wherein the processing circuitry is further configured to: 
 filter a third block and a fourth block included in the second image to generate second filtered data, using values of pixels respectively included in the third block and the fourth block, each of the third block and the fourth block being either a second Intra Pulse Code Modulation (IPCM) block or a second non-IPCM block; 
 determine (i) whether both of the third block and the fourth block are second non-IPCM blocks; (ii) whether both of the third block and the fourth block are second IPCM blocks; or (iii) whether one of the third block and the fourth block is a second IPCM block and the other of the third block and the fourth block is a second non-IPCM block; and 
 generate, when it is determined that one of the third block and the fourth block is a second IPCM block and the other of the third block and the fourth block is a second non-IPCM block, a second reconstructed image, 
 wherein the second reconstructed image includes (i) a part of the second filtered data as the pixels in the second non-IPCM block and (ii) unfiltered pixels in the second IPCM block, instead of a part of the second filtered data, as the pixels in the second IPCM block, 
 wherein prediction and transformation are performed on the second non-IPCM block, and prediction and transformation are not performed on the second IPCM block, 
 wherein the third block is adjacent to the fourth block, and 
 wherein in the filtering of the third block and the fourth block, a fixed value is not used as a second quantization parameter of a second IPCM block.